Nanobubble utilization method and device

ABSTRACT

The present inventors have found the presence of a nanobubble that has not been confirmed conventionally, and established a method for producing nanobubbles. The inventors have determined the theoretically expected characteristics of the produced nanobubbles, found new characteristics by analyzing data experimentally collected, and elucidated the relationship among the characters. Specifically, the inventors have found that a nanobubble has features such as decrease of the buoyant force, increase of the surface area, increase of the surface activity, generation of a local high-pressure field, interface activating action, and sterilizing action thanks to electrostatic polarization. By the association among the features, any of wide variety of objects can be cleaned with high performance and with light environmental load thanks to the function of adsorbing foul components, the function of cleaning the surface of an object quickly, and the sterilizing function, and polluted water can be purified. Nanobubbles can be applied to an organism to recover from fatigue and effectively used for chemical reactions.

TECHNICAL FIELD

The present invention relates to a nanobubble-utilizing method andapparatus for effectively utilizing nanobubbles in various fields byutilizing characteristics of bubbles having a diameter ofnanometer-order, such as increase of surface areas, generation of a highpressure, realization of electrostatic polarization, increase of surfaceactivity, and decrease of a buoyant force.

BACKGROUND ART

Conventionally, various investigations have been made as to microbubbleshaving a diameter of micrometer-order. That is, bubbles having adiameter of about 10 microns are generated by cavitation. Then, it havebeen considered and partially used that the microbubbles are used forenvironment protection by utilizing the function of the microbubblessuch as air-liquid dissolution and floatation or by utilizing thefunction of cleaning water polluted by oil and the like, or are used forpromoting the growth of water-borne animals and plants by utilizing thegrowth promotion effects and the like in culture and the like.

In order to enhance such functions of the microbubbles, it is naturallyconsidered to make the sizes of the bubbles smaller and utilization ofnanobubbles having a diameter of nanometer-order has been considered assmall-sized bubbles.

However, in the conventional technique, there has been no method forconfirming the presence of such bubbles having a diameter ofnanometer-order, that is, nanobubbles. Thus, it has not been confirmedeven as to whether nitrogen or oxygen dissolved within water is presentin a state of molecules or in a state of bubbles with a nanometer-ordersize. Also, there is no apparatus for generating nanobubbles, and it hasnot been confirmed even as to whether or not nanobubbles can begenerated by the conventional cavitation.

Supposing that there are nanobubbles, it is considered that there arenanobubbles of single-component system such as bubble of vapor existingwithin water, for example, and nanobubbles of multi-component systemconsisting of gas, such as nitrogen or oxygen, as air dissolved inwater. Since a small-sized babble having an inner pressure equal to orlarger than the pressure of the bubble of the existing bubbles cannotexist, it is necessary to provide an environment where about 100atmospheric pressure (atms) can be realized. Although the presence ofsuch nanobubbles is supposed by such observation that an air-liquidinterface surface is present at the water confined within a carbonnanotube, this is mere speculation. Also, it is known that bubblesdisappear at the time of the cavitation or subcooled boiling, and it ispredicted bubble with a diameter of nanometer-order is presenttransitionally on the way of the disappearing process of the bubbles.Furthermore, as described above, the nanobubbles of multi-componentsystem is present in the case where air, nitrogen, oxygen or carbondioxide is dissolved in water and is present as bubbles. As thenanobubbles of multi-component system, microbubbles having a diameter ofabout 1 micron was observed but bubbles having a diameter ofnanometer-order less than 1 micron have not been confirmed yet.

Thus, since it has not been confirmed that the nanobubbles are presentwithin water, the existence of the nanobubbles is mere speculation. Evenif it is supposed that the nanobubbles are present, it has not beensolved whether or not the characteristics of the nanobubbles areextended from those of the microbubbles and whether or not thenanobubbles has other characteristics. Also, a method for generating thenanobubbles is merely beyond the compass of imagination. Furthermore,effectively utilization of the nanobubbles has been merely an armchairplan in accordance with speculation extended from the characteristics ofthe conventional microbubbles.

In order to solve such current problems, as a result that the inventorsof the present invention have earnestly investigated, they confirmedthat there exists the nanobubbles and developed an apparatus forgenerating the nanobubbles which was filed as a patent applicationentitled “Apparatus for Generating Nanobubbles” (Japanese PatentApplication No. 2002-145325). Since the technique is described in detailin specification of the patent application, the detailed explanationthereof is omitted but the technique was realized by utilizing anapparatus schematically shown in FIG. 5.

In FIG. 5, a testing room 1 is a room for performing electrolysis ofwater and for generating nanobubbles by the action of an ultrasonic wavegenerating device 2 disposed at the lower portion of the testing room.The testing room is configured by a rectangular pipe made of stainlesssteel and is provided with glass windows at the two side walls thereofso that a person can observe the inner state thereof. The test room hasa length of 40 mm, a width of 40 mm and a height of 270 mm which isseveral times (10 times) of a half wave length (27 mm) of the wave beinggenerated so that a standing wave is generated, as described later. Atop plate made of stainless steel having a discharge port fordischarging a liquid containing bubbles is disposed at the upper end ofthe rectangular pipe, and a bottom plate made of stainless steelattached at the rear surface thereof with the ultrasonic wave generatingdevice 2 having a vibration plate is disposed at the lower end of therectangular pipe.

The ultrasonic wave generating device (SC-100-28 manufactured by STMCo.) has an oscillator made of ferrite having a frequency of 28 kHz. Theoutput of the oscillator is transmitted to the vibration plate togenerate an ultrasonic wave within the test room. An anode forelectrolysis is attached at the bottom plate of the test room 1, and acathode is attached within a pipe for discharging hydrogen which isconnected with the rectangular pipe. A power supply device forelectrolysis (4329A High Resistance Meter manufactured by YokogawaHewlett Packard Co.) is used which has a large resistance value and iscapable of flowing a small amount of current when applied with a voltageof a predetermined constant value.

Distilled water supplied from a distilled water supply pipe 6 isconverted into ultra-pure water by an ultra-pure water manufacturingdevice 5 (Milli-Q Synthesis manufactured by Millipore Co.) and theultra-pure water is supplied through an ultra-pure water pipe 7 providedat the lower end of the test room 1. Within the test room 1, theultra-pure water is electrolyzed so that oxygen is generated from theanode on the surface of the bottom plate, whereby the oxygen thusgenerated is discharged outside from the water as bubbles by the actionof the ultrasonic wave. In this case, nanobubbles are partiallygenerated. Even only by applying ultrasonic wave without performing theelectrolysis, non-visible cavitation is generated by the pressure changeto thereby generate nanobubbles.

A bubble pipe 8 is provided at the upper portion of the test room 1 sothat the bubbles generated in the test room flow into a particle counter4 through the bubble pipe, whereby the particle counter counts thebubbles generated in the above-described manner. The particle counter 4has a first particle counter (KS16 manufactured by Rion Co.) forcounting particles having a diameter of 100 nm or less and a secondcounter (KS17 manufactured by Rion Co.) for counting particles having adiameter of 100 nm or more. Each of the particle counters employs asemiconductor laser for irradiating a laser light with a wavelength ofabout 830 nm as a light source and receives the laser light by a photodiode. The bubbles can circulate in such a manner that the bubbles passthe particle counter 4 and return to the ultra-pure water manufacturingdevice 5.

The above-described particle counter is arranged in such a manner thatthe light is irradiated from the semiconductor laser into the test cellwithin a measuring device, and the change of the intensity of scatteredlight emitted from bubbles or fine particles passing through the laserlight is read to measure diameters of the bubbles or fine particles. Inthis range, the bubbles (or particles) can be recognized as spherical.Also, since the diameter of the bubble (or particle) is almost same asthe wavelength, the relationship between the scattered light intensityI_(θ) and the diameter d of a bubble can be solved by using asimultaneous equation based on the Mie scattering theory.

The conventional distilled and ion exchanged water includes about onehundred thousand fine particles (or fine bubbles) with a diameter of 500nm or more per ml, so that it cannot be distinguished between the fineparticles and the fine bubbles. Thus, at the time of operating theabove-described apparatus, an experimental apparatus for the flowingcharacteristics of the air-liquid interface of the microbubbles isimproved, and the nanobubbles are generated in a state where theultra-pure water manufacturing device is operated continuously and thenumber of the fine particles is reduced to about several per ml. As aresult, according to an experiment described later, it could beconfirmed that nanobubbles are generated within water and existnormally.

First, water is circulated between the ultra-pure water manufacturingdevice and the water within the test portion is purified until thenumber of the particle counter is stabilized. After the number of theparticle counter becomes almost constant, an ultrasonic wave isgenerated by the ultrasonic wave generating device and bubbles generatedis measured by the particle counter. The measurement of the bubbles iscarried out while monitoring the water temperature, a total organiccarbon (TOC) amount of supplied water and the water after passingthrough the test portion, the number of ultra-fine particles, the numberof bubbles and the output current of the ultrasonic wave generatingdevice. In this case, the oxygen density γ within the water (that is, aratio of the density of oxygen within the water with respect tosaturation density thereof of one atm) is 2.0, and the ultrasonic wavehas a wavelength of 28 kHz and an output power of 100 W.

As a result, the experimental results were obtained as shown in FIG. 6.This figure shows a graph representing the densities (number/ml) foreach group of the diameter ranges of the bubbles. That is, this figureshows, as to each group of the diameter rangs, (a) the density beforethe application of the ultrasonic-wave vibration, (b) the density duringthe application of the ultrasonic-wave vibration, (c) the density afterthe application of the ultrasonic-wave vibration, and (b-a) thedifference between before the application of the ultrasonic-wavevibration and the density after the application of the ultrasonic-wavevibration for representing the change of the density of the bubbles dueto the application of the ultrasonic-wave vibration.

According to this experimentation, it was confirmed that there werebubbles having a diameter of at least a nm-order, that is, nanobubbleswithin the water, and further confirmed that there were also nanobubbleshaving a diameter of about 50 nm at a high density. Furthermore,particularly, it was confirmed that nanobubbles were surely generatedwhen the ultrasonic-wave vibration was applied and were existed normallyby applying the ultrasonic-wave vibration.

Also, from FIG. 6, it is understood that nanobubbles of all the sizeswere generated when the ultrasonic-wave vibration was applied, and thatthe smaller the diameter of the bubble was, the larger the density(number/ml) of the bubble was. Furthermore, as is clear from a graphshown in FIG. 7 which represents only the difference (b-a) in FIG. 6,the smaller the diameter of the nanobubbles generated by theultrasonic-wave vibration was, the larger the density (number/ml) of thebubble was. Although the smaller the diameter of the nanobubbles was,the larger the number of the bubbles was, the volume of the bubble isproportional to the cube of the diameter of the bubble. Thus, when themean value of the volume is multiplied at each group of the diameterranges of the bubbles, it was found that the rate of the volume becamelarger as the diameter of the bubble was large.

The utilizing techniques are disclosed in the following documents.

-   Patent document 1: JP-A-2002-119-   Patent document 2: JU-A-4-21381-   Patent document 3: JU-A-55-180425

DISCLOSURE OF THE INVENTION

As described above, the inventors of the present application haveconfirmed that there exists the nanobubbles and filed the patentapplication. As disclosed in the patent application and brieflydescribed above, it was found that nanobubbles could be surely generatedby performing the electrolysis and applying the ultrasonic-wavevibration. Thus, it became a real problem to consider the effectiveutilization of the above-described nanobubbles. Therefore, the inventorsof the present application have elucidated the characteristics of suchnanobubbles, investigated effective usages utilizing suchcharacteristics, and repeated experimentations.

Therefore, an object of the present invention is to provide ananobubble-utilizing method and apparatus for effectively utilizingnanobubbles of which existence was clarified and generation apparatuswas established by the inventors of the present application.

The inventors of the present application elucidated the characteristicsof the above-described nanobubbles and found the following matters. Thatis, the nanobubble with a diameter of about 50 nm to 100 nm has apressure of about several tens atms due to the surface tension withinwater and can generate an air jet when the bubble collapses, whereby thecleaning effect for the surfaces of an object can be expected. Also,since the surface activity of the bubble is high and foil components canbe adsorbed to the interface, the foul component of water can beeffectively removed. In particular, the bubble of an about 100 nmdiameter has a surface area about several ten thousands times as largeas that of a bubble of about several mm diameter usually observed forthe same volume, and the bubble of an about 100 nm diameter is expectedto have a high cleaning speed. Also, according to the calculation resultof the molecular dynamics for air bubbles having a nanometer order sizewithin the water, it is expected that the hydrogen bonds of the waterinteract with one another and the probability where hydrogen atoms existwithin the bubble is large. Thus, it was proved that when such mutualaction of molecules is exerted, the charge separation similar to soapcan be realized at the air-liquid interface due to the bubbles having ananometer-order size, whereby the cleaning promotion effects and theelectrostatic sterilizing effects can be expected.

By utilizing the above-described characteristics of the nanobubbles, thenanobubbles are applied to the cleaning method and apparatus utilizingnanobubbles as an embodiment of the method and apparatus for utilizingnanobubbles of the present invention, and objects are cleaned by usingthe water comprising nanobubbles. In this respect, although it has beenconsidered to clean objects by utilizing air bubbles having a relativelysmall diameter, since the existence of the nanobubbles themselves couldnot be confirmed, it was an armchair plan to clean various kinds ofobjects by the water comprising nanobubbles, that is, to actually cleanvarious kinds of objects by the conventional nanobubbles. The inventorsof the present application proved the existence of the nanobubbles andestablished the method and apparatus for generating the nanobubbles. Asa result, the nanobubbles can be actually utilized for the cleaningmethod and apparatus. Also, the characteristics of the nanobubbles wasconfirmed by actually generating the nanobubbles. In particular, theinventors of the present application have invented the present inventionby finding new characteristics such as the electrolytic separationphenomenon on the surface of the nanobubble.

As another embodiment in which the cleaning method and apparatusutilizing nanobubbles according to the present invention are realizedmore concretely, there is one in which nanotechnology-associatedequipments are cleaned by the ultra-pure water at the time of cleaningobjects by the water comprising nanobubbles. Also, industrial equipmentsare cleaned by the water comprising nanobubbles and an organism iscleaned by the water comprising nanobubbles. The water to be used iselectrolyzed water, ionized alkaline water or acid water. When themicrobubbles are imparted to the water comprising nanobubbles, thefunction of the nanobubbles can be further improved.

Also, since the surface activity of the bubbles is high in thenanobubbles as described above, foul components can be absorbed to theinterface, so that the nanobubbles are effective for removing foulcomponents in water. Also, still another embodiment of the method andapparatus for utilizing the nanobubbles according to the presentinvention is arranged to utilize the nanobubbles so as to absorbpolluted material by utilizing such characteristics that the nanobubbleshave a quite large surface area per volume. Also, microbubbles are mixedto the water so that the nanobubbles having absorbed the pollutedmaterial in this manner move upward within the water.

Furthermore, as described above, since the nanobubble generates an airjet of about several tens atms when the bubble collapses, still anotherembodiment of the method and apparatus for utilizing the nanobubblesaccording to the present invention is arranged to utilize thenanobubbles so as to recover fatigue of an organism by contacting thewater comprising nanobubbles to the organism skin. In this case,microbubbles are also mixed to the water so that the organism contactswith the microbubbles within a bathtub.

Also, since the nanobubble has a quite large surface area per volume,another example of the method and apparatus for utilizing thenanobubbles is arranged by utilizing the characteristics that thechemical reaction can be changed, so that the nanobubbles can beeffectively utilized for various kinds of the chemical reactions. Inthis case, the mechanical reaction is utilized particularly for thenon-equilibrium chemical reaction and the nanobubbles act as a catalyst.

Also, the above-described nanobubbles are utilized so as to be made incontact with plants, particularly, vegetables, fruits, crops, foods andthe like to clean and sterilize them and are also utilized to purify thewater within a pool or a water tank. Furthermore, the above-describednanobubbles are generated stably at least by application of anultrasonic wave to water or by electrolysis. In this case, of course,the application of an ultrasonic wave and the electrolysis can becombined.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram for explaining a utilizing field system which showsthe mutual relationship of the function, action, effects and theutilizing fields of the nanobubble utilizing technique according to thepresent invention.

FIG. 2 is a diagram showing a state of electrostatic polarization causedon the surface of the nanobubble.

FIG. 3 is a diagram for explaining a state where the microbubble isconverted in a solid fine particle after the adsorption of fineparticles on the surface of the nanobubble.

FIG. 4 shows experimental data investigated as to the relationshipbetween Reynolds numbers and resistance coefficients of solid fineparticles and liquidity boundary surface sphere.

FIG. 5 is a schematic diagram showing an experimental apparatus by whichinventors of the present application generated nanobubbles within purewater and observed the nanobubbles.

FIG. 6 is a graph showing the densities of the microbubbles before andduring the operation of an ultrasonic-wave vibrator, obtained by theexperimental apparatus.

FIG. 7 is a graph showing the generation state of the nanobubbles, whichis taken as to only the density difference portions of the graph in FIG.6. A diagram for schematically explaining a transistor.

BEST MODE FOR CARRYING OUT THE INVENTION

As has been already disclosed in the above-described patent application,the inventors of the present application clarified the technique forsurely generating the nanobubbles by the electrolysis or the applicationof an ultrasonic wave. Thus, the inventors of the present applicationhave thought how to effectively utilize the nanobubbles and elucidatedthe characteristics of the nanobubbles, the results of which is shown inFIG. 1.

As is clear from FIG. 1, the nanobubbles can be generated by theapplication of an ultrasonic wave or the electrolysis in not only normalwater but also ultra-pure water, electrolyzed water, or alkaline wateror acid water using ion-exchanged water. The nanobubbles thus generatedhave major characteristics shown by T1 to T5 in the figure.

As is shown in FIG. 1, the nanobubble has a particularly remarkablecharacteristics in increase of the surface area (T2). In this respect,according to the conventional investigation in the microbubbles, it wastheoretically predicted that, when there exist nanobubbles, the surfacearea of the micro bubble increases to further improve thecharacteristics of the microbubble. However, it was uncertain whether ornot there exist the nanobubbles actually. Then, the inventors of thepresent application elucidated for the first time the existence of thenanobubbles and established the mean for generating the nanobubbles.Thus, instead of the conventional supposed discussion, according to thepredicted theory that the nanobubbles exist actually, by comparing ananobubble having a diameter of 100 nm with a bubble having a diameterof 1 mm, the existence of the bubble having characteristics in which thesurface area per volume (specific surface area) is 10,000 times higherwas confirmed.

According to such characteristics, the ability of the bubble forabsorbing materials on the surface thereof can be increased remarkablyand an amount of foul components adsorbed per unit time can beincreased. Also, foul components in a liquid can be adsorbed at a highspeed (K1), the nanobubbles can be utilized for cleaning various kindsof objects (R1), and the nanobubbles can be utilized effectively forpurifying polluted water. Also, since the surface area of the bubbleincreases remarkably, the chemical reaction surface can be increased inthe chemical reaction using the surface as the reaction surface, so thatthe nanobubbles can be utilized effectively in the field of the chemicalreaction (R4).

Also, the nanobubble is remarkable in its generation characteristics(T4) of the local high-pressure field. In the conventional investigationof the microbubbles, the characteristics of the microbubbles werepredicted in the case of supposing that the nanobubble is present.However, as described above, since the existence of the nanobubble wasconfirmed and the means for generating the nanobubbles were established,a pressure Δp within the bubble within the water becomes 30 atms as tothe nanobubble of a 100 nm diameter in accordance with a relationshipamong the pressure Δp within the bubble within the water, the surfacetension σ of the bubble and the diameter of the bubble [Δd=2 σ/d]. Inthis manner, it was confirmed that there existed the bubble which hasthe characteristics of capable of realizing the local high-pressure of30 atms within the bubble.

According to the characteristics, when the nanobubble collides with anobject and collapses, the high-pressure air within the bubble is eruptedto generate an air jet. Thus, the foul components adhered to the surfaceof the object can be surely separated therefrom, so that the high-speedcleaning of the object surface can be realized (K2). Thus, thenanobubble is suitable for cleaning various kinds of objects (R1). Also,the nanobubble may be utilized effectively in the chemical reaction byutilizing the local high-pressure state (R4). Furthermore, when the airjet is applied to an organism by using it for the water within a bathtuband the like, the effects of applying a pressure to the skin of theorganism such as a human body is enhanced, so that the fatiguerecovering effects due to the acupressure effects of chiropractic isimproved. Also, as described above, the bubble exerts the effect ofseparating foul components adhered to the skin surface, the nanobubbleis effective when applied to organism (R3).

Also, the surface of the nanobubble relates to the increase of thesurface area per volume (T2) and the generation of the localhigh-pressure field (T4), which results in the increase of the activityof the surface thereof (T3) to thereby increase the adsorptibity of foulcomponents on the interface. As a result, as described above, inaddition to the increase of the amount of foul components adsorbed perunit time due to the increase of the surface area per unit volume, theeffects of the adsorptibity can be further enhanced. Thus, theadsorption function of foul component within a liquid can be enhanced(K1) and the cleaning ability for various kinds of equipments can beimproved (R1). Also, the nanobubble is effective for purifying pollutedwater (R2).

Furthermore, the nanobubble has a unique characteristics that theelectrostatic polarization can be realized (T5). That is, as shown inFIG. 2, since the hydrogen bonds interact with one another, theelectrostatic polarization occurs in time-average, and the probabilitywhere the hydrogen atoms are present inside the bubble becomes high.Thus, it is possible to theoretically know the characteristics of thebubble through the calculation based on the molecular dynamics.

According to the characteristics, the charge separation similar to theconventional soap can be realized at the air-liquid interface. Thecharge separation acts to separate the foul component adhered to theobject surface, whereby the separation effect of an object can besynergistically enhanced together with the physical separation effect ofthe air jet. Thus, the high-speed cleaning of the object surface is madepossible (K2) and the characteristics can be effectively utilized forthe cleaning and sterilization of various kinds of objects (R1). Also,when the separation effects of the foul components adhered to the objectsurface is applied to an organism (R3), the skins of patients whichcannot be washed with soap due to various kinds of sick can be cleaned.Furthermore, even in the case where the surface active agent can beused, the characteristics is effective for a person who is required toimmediately and entirely wash off the agent. Furthermore, thenanobubbles may be utilized for chemical reactions by using theelectrostatic polarization (R4).

Consideration will be made as to a state where foul components areadhered to the above-described nanobubbles. For example, as is shown inFIG. 3, when the nanobubbles are generated by applying theabove-described ultrasonic wave and the like within the water mixed withpure water and ion exchanged water in which about 10,000 fine particleshaving a specific resistance of 10 MΩ cm and a grain diameter of 0.5 μmor more are present per unit ml and about 1 ppm of TOC (total organiccarbon) is present, at first, the bubble has a liquidity boundarysurface on the surface thereof to form a liquidity boundary surfacesphere, and the coefficient of resistance CD is small. However,impurities immediately adheres to the air-liquid interface surface ofthe nanobubble and the nanobubble becomes similar to a solid fineparticle having a large coefficient of resistance CD.

As is shown in the experimental result shown in FIG. 4, the resistancecoefficients of the liquidity boundary surface sphere with respect tothe respective Reynolds numbers in a state where the nanobubbles of amicrometer-order diameter have just been generated is shown by a lowerside graph in the FIG. 4(b). In contrast, the microbubble having beenconverted into the solid fine particle state increases its resistancecoefficients as shown by a lower side graph in the figure, as is clearfrom the graph showing the case of the water mixed with pure water andion exchanged water. According to the above-described increase of theresistance coefficients in addition to that the nanobubble convertedinto the fine particles state has a characteristics of reduced buoyancy,the nanobubbles converted into the fine particles state can hardly movewithin the liquid and merely float within the liquid.

As described above, it is clear that the peripheral impuritiesimmediately adheres to the nanobubble having been generated within thewater. Thus, the nanobubbles are effective at the time of cleaningvarious objects and also at the time of purifying the polluted watercontaining fine particles and organic substance.

In this manner, since the nanobubbles realize the charge separation atthe air-liquid interface similarly to soap and also have not only thefunction of separating the foul components adhered to the object surfacebut also the function of adsorbing the impurities after being separated,this technique can be applied in place of detergents having beenutilized in the wide fields. Thus, if 10% of the consumed quantity ofdetergents is replaced by this technique in Japan, the replaced energycorresponds to one million barrels of oil according to anothercalculation which also corresponds to an amount of energy of one dayconsumed in Japan. Therefore, this technique is very important for Japanas well as other countries.

When comparing the power consumed at the time of using a washing machinewith the power consumed as the driving energy of an ultrasonic wavevibrator for attaining the cleaning effects which is considered to besurely realized by further investigating and developing hereinafter, itis predicted that an amount of consumed energy for attaining the samecleaning effects is quite smaller in the latter case than the formercase. In this manner, this invention is considered to be the cleaningtechnique of a light environmental load since the present invention iseffective in the reduction of carbon dioxide gas due to the reduction ofa consumed amount of oil resulted from non-use of detergents and thereduction of the driving energy.

Also, according to the realization of the electrostatic polarization(T5), the sterilization effect can be attained by the static electricitythus generated. Thus, particularly, the electrostatic polarization canbe effectively used when it is necessary to sterilize the surface of anobject to be cleaning (K3) at the time of cleaning various kinds ofequipments (R1). Also, the electrostatic polarization can be used forthe cleaning and sterilization by contacting the nanobubbles to plants,particularly vegetables, fruits, crops, foods and the like. Also, theelectrostatic polarization can be used for an organism (R3) to therebyeffectively apply the nanobubbles to a patient whose skin is required tobe sterilized as well as a normal person. Incidentally, thecharacteristics of the electrostatic polarization is considered to beeffectively applied to the chemical reaction according to the necessity.Although the description is omitted since the drawings seem to becomecomplicated, of course, the sterilization action is effective also forthe cleaning of polluted water and can be used for the purification andsterilization of water within a pool or a water tank.

The buoyancy force of the nanobubble reduces remarkably (T1) and becomesalmost zero, so that the bubbles diffuse along the flow and can reachevery surfaces of objects within water. Thus, since the bubbles enterinto fine spaces within the objects to exert the function (K1) ofimproving the adsorption action of foul components within liquid due tothe increase of an amount of the foul components adsorbed per unit timeas described above, the high-speed cleaning function of the objectsurface (K2) and the sterilization function (K3), the cleaning function(R1) of the various kinds of equipments can be enhanced. In this manner,the cleaning of various objects can be performed with a highperformance.

Also, when the nanobubbles are used for an organism, they can be spreadto fine portions of the human body for the acupressure effects by theabove-described air jet, the separation action by a high-pressure causedby the air jet, and the effects similar to that of soap and thesterilization effect by the electrostatic polarization and the like.Incidentally, at the time of utilizing the nanobubbles for an organism,if the organism is an animal such as a fish, it is considered thatnanobubbles can be applied similar to conventional applications ofnanobables to the fish firming, the keeping of flesh fishes, and thelike. In this case, due to the decrease of the buoyancy force of thenanobubbles (T1), the nanobubbles supplied within the water can beeffectively applied to fishes and the like without losing thenanobubbles from the surface side of the water.

Summarizing the above-described matters, due to the main characteristicsof the nanobubbles of the decrease of the buoyancy force (T1), theincrease of the surface area (T2), the increase of the surface activity(T3), the generation of the local high-pressure field (T4) and theestablishment of the electrostatic polarization (T5), the nanobubblesgenerated by the application of an ultrasonic wave or the electrolysiswithin water such as ultra-pure water, electrolyzed water orion-exchanged water can clean various objects such asnanotechnology-associated equipments, industrial equipments and clotheswith the light environmental load with a high performance and withoutusing soap or the like (R1) by the adsorption function of foulcomponents in liquid (K1), the high-speed cleaning function of theobject surface (K2), the sterilization function (K3) and the like. Also,polluted water generated in wide fields as well as polluted watercontaining foul components separated within water in this manner can beeffectively purified (R2) by the adsorption function of foul componentsin liquid, particularly. Furthermore, the various effects can beobtained for an organism such as sterilization, removal of foulcomponents adhered to the object surface by the air jet or soap effects,and acupressure effects by the air jet (R3). Furthermore, thenanobubbles can be effectively utilized for chemical reactions due tothe generation of a local high-pressure field, the establishment of anelectrostatic polarization and the increase of the chemical reactionsurface (R4).

In the case where the conventionally known microbubbles are imparted tothe water where the above-described nanobubbles are present, when foulcomponents adheres to the microbubble, the microbubble is converted intothe solid fine particle state as described above, whereby the resistancecoefficients thereof increases. Also, since the nanobubble has a smalldegree of buoyancy originally, the nanobubbles scarcely move upward inthe liquid surface direction and merely float within the liquid.However, the microbubbles thus imparted adsorb the fine particles of thenanobubbles onto the surface thereof, whereby the microbubbles moveupward due to the buoyancy thereof within the liquid and can be gatheredon the surface of the liquid. Thus, the polluted water can be purifiedmore effectively (R2). The thus gathered nanobubbles which adsorb thefoul components and are converted into the fine particle state can beeasily removed by being scooped up on the surface of the liquid.Incidentally, in the case of not imparting any microbubbles or eveningin the case of imparting the microbubbles in the above-described manner,the nanobubbles can be exhausted outside of the apparatus by providing aseparation means such as a filter at the pure water manufacturingportion in the experimental apparatus shown in FIG. 5.

Also, when the microbubbles are imparted, even in the case where thereare relatively large impurities which can be hardly removed by themicrobubbles at the time of adsorbing foul components, the impuritiescan be effectively adsorbed and removed by the microbubbles like theconventional removing method for polluted water using the microbubbles.Thus, the adsorption function of foul components in liquid (K1) can beenhanced furthermore. Also, when the microbubbles are mixed into abathtub or the like in which the nanobubbles are supplied in theabove-described manner, the conventional acupressure effects can beadded due to the collapse of the relatively large bubbles, whereby thebubbles can be utilized more effectively.

In particular, the techniques of cleaning various objects and purifyingpolluted water using the nanobubbles according to the present inventionare expected to apply a large impact to wide industrial fieldshereinafter. As to the cleaning technique, the techniques are largelyexpected particularly in the technical field relating to nanotechnologysuch as cleaning of semiconductor devices. In such a technical fieldrelating to nanotechnology, it is preferable to use pure water in whichthe nanobubbles are generated.

Also, the technology of the present invention can be used instead ofconventional detergents in the field of the washing including normalfamilies. When this technology is utilized widely, detergents per se andmost of energy required for manufacturing detergents can be reduced.Also, in a view point of the energy efficiency of the ultrasonic wavevibrator, most of the driving power for the washing machine can beremoved. In view of these matters, the environmental load can be madesmall.

In the field of cleaning polluted water in which the development oftechnique more effective than the current technique has been desired,fine particles containing an organic substance can be removed surely byusing the ultrasonic-wave vibrator which can generate the nanobubbleseffectively or by also using the conventional microbubble generatingdevice. Also, the microbubble is arranged to adsorb the nanobubble whichadsorbs fine particles and the like and thus converted into a solid finearticle, whereby the microbubbles can move up on the liquid surface.

According to the present invention, as described above, although it wasexpected that the nanobubbles exist actually but the existence thereofhas not been confirmed yet, the inventors of the present applicationhave clarified that the nanobubbles are present actually and furtherestablished the manufacturing method for the nanobubbles. Also, theinventors of the present application have determined the characteristicsof the nanobubbles being predicted theoretically, then analyzed the dataobtained from the experimentation to discover new characteristics andelucidated the mutual relationship of these characteristics, and thenspecified the fields in which the nanobubbles can be utilizedeffectively. One of the utilization modes thus specified is the cleaningof objects.

Concerning the cleaning of objects, by utilizing all of the functions ofthe nanobubble, that is, the reduction of the buoyancy, the increase ofthe surface area, the increase of the surface activity, the generationof the local high-pressure field, the interface activation effectsimilar to soap by the establishment of the electrostatic polarizationand the sterilization effect by the static electricity are effectivelyused, objects can be cleaned quite effectively by the mutual actionthereof and the multiple effects thereof. Also, the nanobubble can alsobe utilized effectively at the time of purifying polluted water.

Similarly, when the nanobubbles are utilized for the recovery of fatigueof an organism, the fatigue of an organism can be effectively recoveredby the above-described various functions and actions of the nanobubbles.Furthermore, the nanobubbles can be effectively utilized for chemicalreactions by the above-described various functions and actions of thenanobubbles.

INDUSTRIAL APPLICABILITY

As is also shown in FIG. 1, the utilization technology of thenanobubbles according to the present invention can be utilized forcleaning and sterilization of nanotechnology-associated equipments,industrial equipments, clothes, plants, foods and the like, and also canbe utilized for purification of polluted water, for an organism within abathtub or the like and further for various chemical reactions.

1. A cleaning method utilizing nanobubbles, which comprises cleaning anobject with water comprising nanobubbles.
 2. The cleaning methodutilizing nanobubbles according to claim 1, wherein the water isultra-pure water and the object is a nanotechnology-associatedequipment.
 3. The cleaning method utilizing nanobubbles according toclaim 1, wherein the object is an industrial equipment.
 4. The cleaningmethod utilizing nanobubbles according to claim 1, wherein the object isan organism.
 5. The cleaning method utilizing nanobubbles according toclaim 3, wherein the water comprising nanobubbles is electrolyzed water,ionized alkaline water or acid water.
 6. The cleaning method utilizingnanobubbles according to claim 1, wherein the water comprisingnanobubbles further comprises microbubbles.
 7. A cleaning apparatusutilizing nanobubbles, which comprises: a device for generatingnanobubbles within water; and a water supply device for supplying watercomprising nanobubbles to an object to be cleaned.
 8. The cleaningapparatus utilizing nanobubbles according to claim 7, wherein the wateris ultra-pure water and the object is a nanotechnology-associatedequipment.
 9. The cleaning apparatus utilizing nanobubbles according toclaim 7, wherein the object is an industrial equipment.
 10. The cleaningapparatus utilizing nanobubbles according to claim 7, wherein the objectis an organism.
 11. The cleaning apparatus utilizing nanobubblesaccording to claim 9, wherein the water comprising nanobubbles iselectrolyzed water, ionized alkaline water or acid water.
 12. Thecleaning apparatus utilizing nanobubbles according to claim 7, whereinthe water comprising nanobubbles further comprises microbubbles.
 13. Amethod for cleaning polluted water by utilizing nanobubbles, whichcomprises purifying polluted eater with nanobubbles and microbubbles.14. An apparatus for cleaning polluted water by utilizing nanobubbles,which comprises a device for mixing nanobubbles and microbubbles intopolluted water.
 15. A method for recovering fatigue of an organism byutilizing nanobubbles, which comprises contacting water comprisingnanobubbles with the surface of an organism to thereby recover fatigueof the organism.
 16. The method for recovering fatigue of an organism byutilizing nanobubbles according to claim 15, wherein the watercomprising nanobubbles further comprises microbubbles.
 17. The methodfor recovering fatigue of an organism by utilizing nanobubbles accordingto claim 15, wherein a means for contacting the water with the surfaceof an organism is a bathtub.
 18. An apparatus for recovering fatigue ofan organism by utilizing nanobubbles, which comprises: a device forgenerating nanobubbles within water; and a means for contacting watercomprising nanobubbles with the surface of an organism.
 19. Theapparatus for recovering fatigue of an organism by utilizing nanobubblesaccording to claim 18, wherein the water comprising nanobubbles furthercomprises microbubbles.
 20. The apparatus for recovering fatigue of anorganism by utilizing nanobubbles according to claim 18, wherein themeans for contacting water with the surface of an organism is a bathtub.21. A method for a chemical reaction utilizing nanobubbles, whichcomprises carrying out a chemical reaction by utilizing a liquidcomprising nanobubbles.
 22. The method for a chemical reaction utilizingnanobubbles according to claim 21, wherein the chemical reaction is anonequilibrium chemical reaction.
 23. The method for a chemical reactionutilizing nanobubbles according to claim 21, wherein the nanobubbles actas a catalyst in the chemical reaction.
 24. An apparatus for a chemicalreaction utilizing nanobubbles, which comprises utilizing a liquidcomprising nanobubbles for a chemical reaction.
 25. The apparatus for achemical reaction utilizing nanobubbles according to claim 24, whereinthe chemical reaction is a nonequilibrium chemical reaction.
 26. Theapparatus for a chemical reaction utilizing nanobubbles according toclaim 24, wherein the nanobubbles act as a catalyst in the chemicalreaction.
 27. A method for purification and sterilization utilizingnanobubbles, which comprises utilizing water comprising nanobubbles forpurifying and sterilizing a plant.
 28. The method for purification andsterilization utilizing nanobubbles according to claim 27, wherein theplant is at least one of vegetables, fruits, crops and foods.
 29. Anapparatus for purification and sterilization utilizing nanobubbles,which comprises a means for contacting water comprising nanobubbles to aplant to thereby purify and sterilize the plant.
 30. The apparatus forpurification and sterilization utilizing nanobubbles according to claim29, wherein the plant is at least one of vegetables, fruits, crops andfoods.
 31. A method for purification and sterilization utilizingnanobubbles, which comprises purifying and sterilizing water within apool or a water tank by nanobubbles.
 32. An apparatus for purificationand sterilization utilizing nanobubbles, which comprises a device formixing nanobubbles into a pool or a water tank.
 33. The method accordingto claim 1, wherein the nanobubbles are generated at least byapplication of an ultrasonic wave or by electrolysis.
 34. The methodaccording to claim 13, wherein the nanobubbles are generated at least byapplication of an ultrasonic wave or by electrolysis.
 35. The methodaccording to claim 15, wherein the nanobubbles are generated at least byapplication of an ultrasonic wave or by electrolysis.
 36. The methodaccording to claim 21, wherein the nanobubbles are generated at least byapplication of an ultrasonic wave or by electrolysis.
 37. The methodaccording to claim 29, wherein the nanobubbles are generated at least byapplication of an ultrasonic wave or by electrolysis.
 38. The methodaccording to claim 31, wherein the nanobubbles are generated at least byapplication of an ultrasonic wave or by electrolysis.